Insulator for electric wires.



No. 879,038. PATENTED FEB. 11, 1908.

J. CALDWELL.

INSULATOR FOR ELECTRIC WIRES. APPLICATION FILED AUG. 7. 1907.

WITNESSES W fl/NVENTOAi Alforlley lator.

PATENT OFFICE.

JOHN CALDWELL, OF PHILADELPHIA, PENNSYLVANIA.

INSULATOR FOR ELECTRIC WIRES.

Specification of Letters Patent.

Patented Feb. 11, 1908.

Application filed August 7. 1907. Serial No. 387.516-

To all whom it may concern:

Be it known that I, JOHN CALDWELL, a citi zen of the United States, residing at Philai delphia. in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improve ments in Insulators for Electric l/Vires; and I do hereby declare l the following to be a full, clear, and exact description of the invention, such as will enal o others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters and figures of reference marked thereon, which form a part of this specification.

This invention relates to new and useful improvements in insulators for electric wires and the object in view is to produce a means whereby the line wire may be prevented from twisting or slipping, and consists essentiall in the provision of an insulator havin a tnangular outlined groove formed preferably above the core of the insulator.

My invention comprises various details of construction and combinations and arrangements of parts which will be hereinafter fully described and then specifically defined in the appended claims.

I illustrate myinvention in the accompanying drawings, in which:

Figure 1 is a perspective view of my insu- Fig. 2 is a sectional view through the insulator, and Fig. 3 is a side elevation.

Reference now being had to the details of the drawings by letter, A desi nates an insulator, preferably of the usual shape, provided with a hollow center for the reception of a su porter.

' designates a groove, the bottom of which is of triangular shape, having preferably three angles, and said groove adjacent to the ends of the angles is widened as at D, as shown, for the P111)OS6 of facilitating the tyin of the wire and of relieving parts of the insuIator from the strain in tying.

l E designates a tie wire, which is passed l about one of the angles in the groove or recess and its ends are twisted about the line wire, which latter is held in the recess and g against one of the straight portions of the i bottomof the recess.

By the provision of the peculiarly formed insulator embodying my invention, hard drawn copper wire may be fastened securely without twisting or kinking the line wire and which it is found possible to do when the wire is fastened to a circular groove of an insulator. As hard drawn copper wire is exceedingly brittle, it will not stand'the bending and twisting that iron wire will and the fact of the wires used upon the circular outlined re- 1 cesses of insulators not standing the bending and twisting which comes upon them has been the means of a great deal of trouble that electrical companies have had to contend with.

What I claim to be new is 1. An insulator having a groove at right angles to its length, the bottom of said groove forming the three faces of the triangle, a line wire held against one of the straight faces of the bottom of the groove, and a tie wire engaging the other two faces and fastened about the line wire, as set forth.

2. An insulator having a groove at right angles to its length, the bottom of said groove forming the three faces of the triangle, a line wire held against one of the straight faces of the bottom of the groove, a tie wire engaging the other two faces and fastened about the line wire, said groove having widened )orthe bottom of the groove, as

Witnesses Geo. LIN, Wm. l un'l tions at the angles formed by the straight 

